While a fuel tank for liquid fuel can largely assume any shape making possible an efficient utilization of existing hollow spaces or clearances of the body of the motor vehicle, the configuration possibilities with pressurized gas tanks are severely restricted by the necessity that the tank has to withstand a high internal pressure without being deformed. In order to guarantee the shape retention of a pressurized gas tank the latter should have a circular cross section in at least one section plane and an adaptation to a hollow space available for the tank with dimensions that are different in three space directions can substantially only take place in that a plurality of pressure vessels of substantially cylindrical shape, whose diameter and length in each case can be adapted to a first or a second dimension of the hollow space, are installed next to one another in a quantity adapted to the third dimension.
The installation of a plurality of pressurized gas tanks instead of a single tank requires increased work expenditure and is correspondingly expensive. In order to simplify the installation of the pressurized gas tank it has been suggested for example in DE 20 2007 015 487 U1 to combine two pressurized gas tanks and one carrier body having concave flanks facing the pressurized gas tanks into one tank module which as a single assembly can be mounted under the floor of a motor vehicle in a manner comparable to a tank.
The carrier body of this known tank module comprises an elongated rail which in the mounted state extends in a substantially triangular intermediate space delimited by the vehicle floor and the two pressurized gas tanks and from which two arms, which on both sides are provided with concave flanks, stand away downwards and engage through between the pressurized gas tanks. The fuel tanks are fixed to the carrier body with the help of clamping straps whose two ends in each case are anchored to the rail and of which in each case a middle portion is tightly screwed to a free lower end of the arms. The screw that tautens such a clamping strap has to be securely anchored at the end of the arm so as not to be torn loose through the tension of the strap and through the shocks acting on the pressurized gas tanks while driving. The considerable material thickness of the carrier body required for this does not only result in high material costs during the manufacture of the carrier body but also increases the fuel consumption of a vehicle on which the tank module is mounted. The conventional support body is manufactured through extrusion, wherein after the extrusion a material-removing machining is still required in order to obtain the final shape of the carrier body. This type of manufacture requires major effort, on the one hand because of the costs of the tools required for manufacturing the extruded profile and on the other hand due to the expensive subsequent machining.
At least one object is to create a tank module for a motor vehicle which is light in weight and inexpensive to manufacture. In addition, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.